Steps
1. Heat olive oil in a skillet over medium heat.
2. Add diced onion and sauté until translucent, about 3-4 minutes.
3. Stir in minced garlic, cumin, chili powder, and salt, cooking for another minute.
4. Add the black beans to the skillet, stirring to combine, and cook for 5 minutes until heated through.
5. In another pan, warm the corn tortillas for about 30 seconds on each side.
6. Assemble the tacos by placing the black bean mixture in the tortillas, topping with avocado slices and fresh cilantro.
7. Serve with a lime wedge on the side.